Compound engine



(No Model.)

S. M. VAAUCLAIN. GOMPOUND ENGINE.

No. 431,860. Patented July 8, 1890.

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v UNTnD STATES PATENT SAMUEL M. VAUCLAIN, OF PHILADELPHIA, PENNSYLVANIA.

COMPOUND ENGINE.

SPECIFICATION forming part of Letters Patent No. 431,860, dated July 8, 1890.

Application tiled February S. 1890. Serial No. 339,721. (No model.)

To all 'wh/0m it r11/wy concern:

Be it known that I, SAMUEL M. VAUCLAIN, a citizen of the United States, and a resident of Philadelphia, Pennsylvania, have invented certain Improvements in Compound Engines, of which the following' is a specification.

rlhe object of my invention is to provide in acompound engine or locomotive a device which will to a certain extent equalize the strain on the connecting' devices of the high andA low pressure piston-rods when starting a train, and at the same time secure the desired extra power for starting heavy trains or loads. This object I attain in the following manner, reference being had to the accompanying drawings, in which- Figure l is a side View of a locomotive-cylindercasting, showing my improvement. Fig. 2 is a sectional View of the cylinders of acompound engine, showing my improvement. Fig. 3 is an end view of the cylinder shown in Fig. 2. Fig. 4 is a sectional view of the cylinders, the pistoirrods of which are connected to cranks diametrically opposite each other; and Fig. 5 is a sectional view of the valve. Y

I will describe my invention as applied to the cylinder of a compound locomotive; but it will be understood thatmy invention can be applied to a stationary or marine engine as well.

A is the high-pressure cylinder, B the lowpressure cylinder, and D the valve for controlling the inlet and exhaust of steam into and from the high and low pressure cylinders.

a is the piston of the high-pressure cylinder, and b the pistou ol' the lowpressure cylinder.

In the arrangement shown in Figs. l, 2,and 3 the piston-rods of the high and lou7 pressure cylinders are connected together by ,a crosshead, the pistons working together. Theinlet and exhaust ports of the high-pressure cylinder are shown at c c', and the inlet and exu haust ports of the low-pressure cylinder at d d', the several ports connecting with the valvechamber, and the valve D controlling the admission of steam thereto and the exhaust of steam therefrom.

E is a passage connecting both ends of the high-pressure cylinder, consisting, in the present instance, of an ordinary pipe E', tapped into the cylinder, as shown, and provided at each end with a suitable valve e c-i u the present instance in the form of a plug-valve; but it will be understood that any form of valve may be used in carrying out luy-invention, and in place of the two valves shown in Figs. l and 2 a single valve may be used, as shown in Fig. 4, and instead of using the pipe E to connect the two ends of the cylinder a passage may be formed in the casting of the cyl inder, as shown in said Fig. 4;. A lever e on each plug-valve is connected to a rod F, an extension F of Which passes to the cab of the engine, and is under the control of the engineer, so that the valve can be opened or closed by the simple longitudinal movement of the rod.

Two Valves are employed at each end ofthe passage E instead of the central valve, to prevent the loss of steam at each exhaust-,which would be contained in the pipe if a single valve was used; but l do not restrict myself to this construction, as a single valve in some cases may be found preferable.

The action of the steam is as follows: If, for instance, steam is admitted in front of the hi gh-pressu re piston, the valves e e are opened and communication established with both ends of the cylinder through the passage E. The steam wire-draws through the passage into the rear end of the high-pressure cylinder, thence through the exhaust-passage to the valve D, and is admitted to the forward end of the low-pressure cylinder through the inletpassage d. Thus the first movement of the engine is what may be termed a Lcompound movement. Vhen the engine has started well, the valves or cocks e c are closed. The engine then works on the compound principle in the usual manner.

By the above-described mechanism, therefore, I am enabled to more readily start a train on a grade or a train that is heavily loaded than heretofore, owing to the fact that the compound action takes place immediately on the first stroke of the engine, at the same time equalizing the strain to a certain extent on both the high and low pressure pistons.

In Fig. 4 the piston-rods of the high and low pressure cylinders are not connected together by a cross-head; but each are connected to a crank, one being opposite the other,

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so that in this case the steam in the rear of the high-pressure cylinder would pass to the rear of the low-pressure cylinder.

I claim as my inventionl. The combination, in a compound engine, of the high and low pressure cylinders, apassage forming a communication between the front and the rear of the high-pressure cylinder with a valve controlling the flow of steam through said passage from one end ofthe cylinder to the other, substantially as described.

2. The combination, in ahigh an d low pressure cylinder, a Valve or valves therefor, apassage communicating with each end 0f the high-pressure cylinder with two valves, one at each end of the passage, said Valves being under the control of the engineer, and adapted to allow or cut off the flow of steam SAMUEL M. VAUCLAIN.

NVitnesses:

WM. RHODES, J r., FRANK H. MAssEY. 

